/**
 * @author       Richard Davey <rich@photonstorm.com>
 * @copyright    2020 Photon Storm Ltd.
 * @license      {@link https://opensource.org/licenses/MIT|MIT License}
 */

 var Class = require('../../utils/Class');
 var CONST = require('../const');
 var FileTypesManager = require('../FileTypesManager');
 var JSONFile = require('./JSONFile.js');
 
 /**
  * @classdesc
  * A single JSON Pack File suitable for loading by the Loader.
  *
  * These are created when you use the Phaser.Loader.LoaderPlugin#pack method and are not typically created directly.
  *
  * For documentation about what all the arguments and configuration options mean please see Phaser.Loader.LoaderPlugin#pack.
  *
  * @class PackFile
  * @extends Phaser.Loader.File
  * @memberof Phaser.Loader.FileTypes
  * @constructor
  * @since 3.7.0
  *
  * @param {Phaser.Loader.LoaderPlugin} loader - A reference to the Loader that is responsible for this file.
  * @param {(string|Phaser.Types.Loader.FileTypes.PackFileConfig)} key - The key to use for this file, or a file configuration object.
  * @param {string} [url] - The absolute or relative URL to load this file from. If undefined or `null` it will be set to `<key>.json`, i.e. if `key` was "alien" then the URL will be "alien.json".
  * @param {Phaser.Types.Loader.XHRSettingsObject} [xhrSettings] - Extra XHR Settings specifically for this file.
  * @param {string} [dataKey] - When the JSON file loads only this property will be stored in the Cache.
  */
 var PackFile = new Class({
 
     Extends: JSONFile,
 
     initialize:
 
     //  url can either be a string, in which case it is treated like a proper url, or an object, in which case it is treated as a ready-made JS Object
     //  dataKey allows you to pluck a specific object out of the JSON and put just that into the cache, rather than the whole thing
 
     function PackFile (loader, key, url, xhrSettings, dataKey)
     {
         JSONFile.call(this, loader, key, url, xhrSettings, dataKey);
 
         this.type = 'packfile';
     },
 
     /**
      * Called automatically by Loader.nextFile.
      * This method controls what extra work this File does with its loaded data.
      *
      * @method Phaser.Loader.FileTypes.PackFile#onProcess
      * @since 3.7.0
      */
     onProcess: function ()
     {
         if (this.state !== CONST.FILE_POPULATED)
         {
             this.state = CONST.FILE_PROCESSING;
 
             this.data = JSON.parse(this.xhrLoader.responseText);
         }
 
         //  Let's pass the pack file data over to the Loader ...
         this.loader.addPack(this.data, this.config);
 
         this.onProcessComplete();
     }
 
 });
 
 /**
  * Adds a JSON File Pack, or array of packs, to the current load queue.
  *
  * You can call this method from within your Scene's `preload`, along with any other files you wish to load:
  *
  * ```javascript
  * function preload ()
  * {
  *     this.load.pack('level1', 'data/Level1Files.json');
  * }
  * ```
  *
  * A File Pack is a JSON file (or object) that contains details about other files that should be added into the Loader.
  * Here is a small example:
  *
  * ```json
  * {
  *    "test1": {
  *        "files": [
  *            {
  *                "type": "image",
  *                "key": "taikodrummaster",
  *                "url": "assets/pics/taikodrummaster.jpg"
  *            },
  *            {
  *                "type": "image",
  *                "key": "sukasuka-chtholly",
  *                "url": "assets/pics/sukasuka-chtholly.png"
  *            }
  *        ]
  *    },
  *    "meta": {
  *        "generated": "1401380327373",
  *        "app": "Phaser 3 Asset Packer",
  *        "url": "https://phaser.io",
  *        "version": "1.0",
  *        "copyright": "Photon Storm Ltd. 2018"
  *    }
  * }
  * ```
  *
  * The pack can be split into sections. In the example above you'll see a section called `test1. You can tell
  * the `load.pack` method to parse only a particular section of a pack. The pack is stored in the JSON Cache,
  * so you can pass it to the Loader to process additional sections as needed in your game, or you can just load
  * them all at once without specifying anything.
  *
  * The pack file can contain an entry for any type of file that Phaser can load. The object structures exactly
  * match that of the file type configs, and all properties available within the file type configs can be used
  * in the pack file too.
  *
  * The file is **not** loaded right away. It is added to a queue ready to be loaded either when the loader starts,
  * or if it's already running, when the next free load slot becomes available. This happens automatically if you
  * are calling this from within the Scene's `preload` method, or a related callback. Because the file is queued
  * it means you cannot use the file immediately after calling this method, but must wait for the file to complete.
  * The typical flow for a Phaser Scene is that you load assets in the Scene's `preload` method and then when the
  * Scene's `create` method is called you are guaranteed that all of those assets are ready for use and have been
  * loaded.
  *
  * If you call this from outside of `preload` then you are responsible for starting the Loader afterwards and monitoring
  * its events to know when it's safe to use the asset. Please see the Phaser.Loader.LoaderPlugin class for more details.
  *
  * The key must be a unique String. It is used to add the file to the global JSON Cache upon a successful load.
  * The key should be unique both in terms of files being loaded and files already present in the JSON Cache.
  * Loading a file using a key that is already taken will result in a warning. If you wish to replace an existing file
  * then remove it from the JSON Cache first, before loading a new one.
  *
  * Instead of passing arguments you can pass a configuration object, such as:
  *
  * ```javascript
  * this.load.pack({
  *     key: 'level1',
  *     url: 'data/Level1Files.json'
  * });
  * ```
  *
  * See the documentation for `Phaser.Types.Loader.FileTypes.PackFileConfig` for more details.
  *
  * If you have specified a prefix in the loader, via `Loader.setPrefix` then this value will be prepended to this files
  * key. For example, if the prefix was `LEVEL1.` and the key was `Waves` the final key will be `LEVEL1.Waves` and
  * this is what you would use to retrieve the text from the JSON Cache.
  *
  * The URL can be relative or absolute. If the URL is relative the `Loader.baseURL` and `Loader.path` values will be prepended to it.
  *
  * If the URL isn't specified the Loader will take the key and create a filename from that. For example if the key is "data"
  * and no URL is given then the Loader will set the URL to be "data.json". It will always add `.json` as the extension, although
  * this can be overridden if using an object instead of method arguments. If you do not desire this action then provide a URL.
  *
  * You can also optionally provide a `dataKey` to use. This allows you to extract only a part of the JSON and store it in the Cache,
  * rather than the whole file. For example, if your JSON data had a structure like this:
  *
  * ```json
  * {
  *     "level1": {
  *         "baddies": {
  *             "aliens": {},
  *             "boss": {}
  *         }
  *     },
  *     "level2": {},
  *     "level3": {}
  * }
  * ```
  *
  * And you only wanted to store the `boss` data in the Cache, then you could pass `level1.baddies.boss`as the `dataKey`.
  *
  * Note: The ability to load this type of file will only be available if the Pack File type has been built into Phaser.
  * It is available in the default build but can be excluded from custom builds.
  *
  * @method Phaser.Loader.LoaderPlugin#pack
  * @fires Phaser.Loader.LoaderPlugin#ADD
  * @since 3.7.0
  *
  * @param {(string|Phaser.Types.Loader.FileTypes.PackFileConfig|Phaser.Types.Loader.FileTypes.PackFileConfig[])} key - The key to use for this file, or a file configuration object, or array of them.
  * @param {string} [url] - The absolute or relative URL to load this file from. If undefined or `null` it will be set to `<key>.json`, i.e. if `key` was "alien" then the URL will be "alien.json".
  * @param {string} [dataKey] - When the JSON file loads only this property will be stored in the Cache.
  * @param {Phaser.Types.Loader.XHRSettingsObject} [xhrSettings] - An XHR Settings configuration object. Used in replacement of the Loaders default XHR Settings.
  *
  * @return {this} The Loader instance.
  */
 FileTypesManager.register('pack', function (key, url, packKey, xhrSettings)
 {
     //  Supports an Object file definition in the key argument
     //  Or an array of objects in the key argument
     //  Or a single entry where all arguments have been defined
 
     if (Array.isArray(key))
     {
         for (var i = 0; i < key.length; i++)
         {
             this.addFile(new PackFile(this, key[i]));
         }
     }
     else
     {
         this.addFile(new PackFile(this, key, url, xhrSettings, packKey));
     }
 
     return this;
 });
 
 module.exports = PackFile;
 